Welcome to Geekzone... Is this Exchange server inside the same network as your PC + cradle?

If you have your own DNS server on this network, make sure the FQDN (Fully Qualified Domain Name) used externally to allow synchronisation is also correctly entered in your internal DNS server.

If you don't have a DNS server, you can update the hosts files (c:\windows\system32\drivers\etc\hosts) and add the FDQN with its internal IP address. This will be valid for your Apache when in the cradle, and when connected via CDMA or Wi-Fi from an external network it will use the public DNS.